Rock-drill.



J. E. BLACKBURN.

ROCK DRILL.

APPLICATION FILED JULY 17, 1912.

SZZQ Patented Apr. 1, 1913.

JULIAN E. BLACKBURN, OF TEXARKANA, TEXAS.

noon-DRILL.

Specification of Letters Patent.

Application filed July 17, 1912. Serial No. 710,073.

Patented Alir. 1,1913.

To all whom it may concern .Be it known that I, JULIAN E. BLACK- BURN, acitizen of the United States, residing at Texarkana, in the county ofBowie and State of Texas, have invented new and useful Improvements inRock-Drills, of which the following is a specification.

This invention has relation to drill points designed most especially forboring rocks, the purpose being the provision of a composite drillembodying an extremely hard substance in granular or other comminuted orbroken up form and a binder for holding the particles together. 1

In accordance with this invention adamant either in the form of metal ormineral and in small or granular form is held together by a binder, suchas Portland cement rock or other substance to be cut through in theoperation of the drill.

The invention consists of the novel features, details of constructionand combination of parts, which hereinafter will be.

more particularly set forth, illustrated; in the accompanying drawing,and pointed out in the appended claim.

Referring to the drawing, forming a part of the spec1fication, Figure lis a side view of a drill point embodying the invention. Fig. 2 is avertical central section of the drill point.

Corresponding and like parts are referred to in the followingdescription, and indicated in all the views of the drawing, by the samereference characters.

A drill point constructed in accordance with this invention comprisesadamant in small particles and a binder having said particles of adamantembedded therein and held together thereby. The adamant may consist ofany hard substance either of metal or mineral. The metal may consist ofbroken files or pieces of hardened steel. The mineral may consist ofcorundum, corundum sparor other extremely hard substance which willresist abrasive action. The size of the pieces or particles of theadamant.

' may vary and will depend largely upon the to a consistency to flow soas to enter the spaces or interstices between the particles of theadamant.

innumerable sharp edges which. latter are The adamantby reason of theirregular shape of its particles presents noteasily dulled because ofthe nature of points of the adamant, thereby resulting in the formationof a drill which is practically self-sharpening and rapid in action.

In the specific formation of the drill it is 'hollow and in operationforms an annular cut, the .core passing within the drill and beingbroken up into small particles by means of an inner project-ion so thatsuch particles may be quickly removed by the water employed for washingout the bore and keeping the drill cool,.thereby enabling the drill tobe continuous in operation when cutting through strata of rock.

As shown most clearly in Fig; 2 of the drawings the drill pointhas acoupling end 1 which is externally threaded to make connection with adrill rod such as commonly employed in rock drilling. The body portionof the drill point comprises an outer shell or casing 2 and an innershell or casing 3. These shells or casings 2 and 3may be of any len hand have a concentric arrangement, being spaced apart a proper distanceso as to receive between them the composition such as adamant and abinder which forms the essential feature of the invention. The outershell or casing 2 has a plurality of openings 6'midway of its ends and aplurality of openings 7 near its lower end or the cutting-edge of thedrill. These openings 6 and 7 admit of the composition coming flush withthe outer side of the drill so as to resist the abrasive action andthereby prevent the rapid wearing away of the outer shell or casing. Aprojection 5 is provided upon the inner side of the inner shell or casing 3 and is of such formation as to readilybreak up the core passingthrough the drill when the latter is in operation. 'lhe'pro- JGCtlOIl 5tapers toward itslower end and is of hardened steel so as to withstandthe work for which it is intended. The two shells 2 and 3 arejoined'near their upper ends and are separated at their lower ends so asto expose the composition. When constructing a drill in accordance withthe invention the annular space between the two shells is filled withadamant such as herein indicated, after which the binding material ispoured into the annular space. and fills the inter-- stices between theparticles of adamant. After the binding material has set or hardened thedrill is ready for use in the manner well understood, the. same beingcoupled to the lower end of the drill rod, the latter being rotated andthe drill cutting an annular channel, the central portion or core of therock or other substance cut through passing upwardly into the center ofthe drill and being broken up by means of the projection or breaker 5,thereby enabling the small particles to be removed from the bore byflooding the same in the manner well understood.

From the foregoing description, taken in connection with theaccompanying drawing,

the advantages of the construction and of the method of operation willbe readily apparent to those skilled in the art to which the inventionappertains, and while I have described the principle of operation of theinvention, together with the device which I now consider to be the bestembodiment thereof, I desire to have it understood that the device shownis merely illustrative, and that such changes may be made when desiredas are within the scope of the claim appended hereto.

Having thus described the invention what is claimed as new, is

A drill comprising concentric shells and a composition filling the spaceformed between said shells and comprising particles of adamant, and abinder having said adamantv embedded therein, the oiiter shell havingopenings in its sides and near the cutting edge of the drill and havingthe composi? tion extending through said openings.

In testimony whereof I afiix my signature in presence of two witnesses.

JULIAN E. BLACKBURN.

Witnesses: ALFRED MARSHAN, E. B. GREEK.

